I. Field
The present invention relates generally to the operation of communication devices, and more particularly, to a system for diverse path antenna selection to receive signals in a communication device.
II. Description of the Related Art
Wireless communication networks are currently in widespread use to allow mobile terminal users to wirelessly communicate with each other and other network entities. Increasingly, mobile terminals are being used to receive both voice communications and data services. However, during operation, mobile terminals may experience the effects of Rayleigh signal fading and/or other transmission distortions that reduce performance. For example, Rayleigh signal fading can occur when multiple out-of-phase versions of the same signal arrive at the receiving antenna. The out-of-phase versions tend to cancel each other and yield a degraded received signal.
One technique used to reduce the effects of signal fading utilizes multiple antennas coupled to primary and diverse receiving paths, respectively, at the receiving device. The antennas are physically space apart from each other, and the primary receive path processes signals received by the first antenna while the diverse receive path processes signals received by the second antenna. By combining the signals on the two receive paths, the effects of signal fading can be reduced. Typically, the second antenna may be incorporated into the housing of the device so as to be less visible. Furthermore, the second antenna and its associated diverse receive path electronics may be constructed using less expensive components and offer lower performance (i.e., less sensitivity) than the first antenna and the primary receive path.
As the availability of wireless services have increased, it would be desirable to be able to receive and process multiple information signals at one time. For example, it is possible for a mobile terminal to receive voice calls, paging messages, data and multimedia services, and positioning signals, such as global positioning signals (GPS). Unfortunately, typical terminals having a static diverse receive path and generally utilize that path only to process signals to reduce transmission effects, such as signal fading. Furthermore, due to cost constraints, the second antenna may not offer the performance of the primary antenna. Thus, current devices are generally limited to processing only one information signal at a time. As a result, the capabilities and functionality of mobile terminals having diverse path processing may be unnecessarily limited and/or underutilized.
Therefore, it would be desirable to have a system that utilizes the diverse receive path in a communication device to provide additional functionality and/or flexibility. For example, it would be desirable to process one or more information signals at the same time in a mobile device.